1. Technical Field
The present invention relates to a swing analyzing device, a swing analyzing program, and a recording medium on which the swing analyzing program is recorded.
2. Related Art
In sports such as golf, tennis, and baseball, it is considered that competitive abilities can be enhanced by improving the rhythm of a swing. Particularly in golf, since a player hits a ball at rest, there is a view that the more stabilized the rhythm (allocation of time) of each of phases (back swing, top, down swing, impact, and follow through) is, the better the swing is. Therefore, some training tools or the like measure variations in the times of the phases to provide information for analysis. Moreover, JP-A-10-43349 (Patent Document 1) proposes a method in which acceleration of a trainee's body is detected and information of the acceleration is analyzed to calculate a back-swing period, a down-swing (forward-swing) period, a follow-through period, and the like. Further, JP-A-2010-68947 (Patent Document 2) proposes a method in which a motion sensor such as an angular velocity sensor is mounted on a site capable of detecting the movement of a user's trunk axis to measure an angular velocity generated by a golf swing and information of the angular velocity is analyzed to calculate the times of back swing, down swing, follow through, and the like.
However, since the acceleration information is used in the method of Patent Document 1, it is hard to detect detailed information such as the extent of a lag at top (whether a club head is swung down after a slow lag at top or is immediately swung down). Therefore, information capable of being provided for swing analysis is limited. Further, although the rhythm of a swing having a large movement such as a full swing can be detected in the method of Patent Document 1, it is necessary when detecting the rhythm of a swing having a small movement such as putting to mount an acceleration sensor on a club head, which is troublesome to handle.
Moreover, the method of Patent Document 2 calculates the rhythm of each of phases of a swing on the assumption that since in a correct golf swing, the trunk axis above the right foot is shifted to that above the left foot before and after an impact, a first peak and a second peak as two turning points (inflection points of a wave form) appear in a change in angular velocity. However, this assumption sometimes breaks down depending on user's characteristics, and therefore, a precise rhythm cannot always be detected. Moreover, also in the case of a swing with a small movement such as putting, it is considered that there is no guarantee that two distinct turning points appear in a change in angular velocity. Further, since it is necessary in the method of Patent Document 2 to detect the movement of the user's trunk axis, the position at which the angular velocity sensor is mounted or the posture is largely restricted, which is also troublesome to handle.